Recording thermometer



March 5, 1935. 5 WARDENBURG 1,993,637

RECORDING THERMOMETER Filed March 3, 1932 2 Sheets- Sheet. 1

INVENTOR BERNHARD G. WARDENBURG av ms ATTORNEYS MMM March 5, 1935. B. s. WARDENBURG RECORDING THERMOME'IER Filed March 3, 1932 2 Sheets-Sheet 2 Nun INVENTOR BERNHARD G. WARDENBURG av HIS A'r'ronuzvl Patented Mus 1935 I v f '3' 1 993 537 Bed G. Wardenhurg, Toledo, Qhio, ignor to Mote Meter Gauge & Equipment Corporation, Toledo, Qhio, a corporation oi Dela 1.1.

Application l 3,, i232, Serial No. 596,618

2? l a (El. R -52} This invention relates to recording thermomthereto a fixed shaft 27. A Bourdon tube 28 and eters, and more particularly to the type comabi-metallic compensating spring 29 aremounted prising a distance'type temperature responsive coaxial with the shaft 27. mechanism a recording mechanism, whereby The Bourdon tube 28 is preferably flattened as 5 a continuous record may be kept of temperature shown, and provided with a reinforcing rib 30, 5

conditions at a point remote from the instruwhich tapers from the fixed end of the Bourdon ment. spring toward the free end thereof. The fixed Objectsof the invention are to simplify and end of the Bourdon spring -is rigidly secured in improve the construction and operation of instrua slotted post 31 mounted on the base plate 28.

1o ments of this character, to reduce the friction The expansible fiuidis supplied to the Bourdon of theparts of the temperature responsive mechtube 28 by a capillary tube 32, which is coiled anism to a minimum while insuring positive aconce around the Bourdon spring and extends tion thereof, and to render the same otherwise therefrom into a sheath 33, the end 34 of which well adapted for the purposes set forth. is mounted in a clamp 35 carried by the sup- 15. Other objects and features of'novelty will be porting plate 25. The capillary tube 32 extends 5 apparent as the following description proceeds, through the sheath 33 to a bulb located at the reference being had to the accompany drawings, point remote from the instrument, where the in which temperature conditions occur which are to be Figure 1 is a partial elevation of a recording recorded.

go thermometer provided with a temperature re- The Bourdon tube 28 and the compensating g0 sponsive mechanism according to the preferred spring 29 are axially spaced along the shaft 27. embodiment of the present invention, parts of This spacing permits them to be wound with the chart and casing being broken away to relatively large inside and outside diameters. show the internal mechanism; Thus the inner ends of both the Bourdon tube Figure 2 is an enlarged detail elevation of the and the compensating spring are spaced from 25 temperature responsive mechanism shown in the shaft 27. This arrangement not only avoids Figure 1; and friction, but also afi'ords free operation of the Figure 3 is a section taken along the line 3-3 inner ends about the shaft 27 concentrically of Figure 2. therewith, and gives greater leverage and more so In Figure 1 a wall type of recording thermompositive operation.

eter is shown, which comprises a circular casing As the outer end 'of the compensating spring 10 having a removable annular flange 11 at the is of greater diameter than the inner end of the front thereof, and defining a centralcircular Bourdon tube, a member 36 isprovlded thereopening' 12 through which a chart 13 is visible. between for connecting these ends- This mem- The chart 13 is detachablysecuredto a hub 14 her 36 is preferably a sheet metal strip, the 35 which is driven at a uniform angular speed by greater portion ofwhich extends radially with clockwork contained in a casing 15.. respect to the shaft 27, but is out of contact The temperature iscontinuously recorded upon therewith. The inner endof the member 36 the char-1:113 by a penld carried by the outer is bent laterally and secured to the inner end of end of a pen arm 1711. This pen arm comprises the Bourdon spring 28." The outer end of the 40 an angularly adjustable extension of one arm of member 36 is originally T-shaped. the wings 38 a rock shaft 17 journaled on a bracket 18 sethereof being bent inwardly to secure the outer cured to the rear wall of the .casing 10. The end of the compensating spring 29 therebetween. other arm of the rock shaft 17 comprises a slotted A lever 40 is Journaled on the outer end of the portion 19 which is angularly disposed with refixed shaft 27 and has an arm 41 bent inwardly 45 spect to the pen arm 17. A block 22 is slidable .and'secured to the inner end of the compensating in the slot of the arm 19 and is pivoted to one spring 29. The outer end of the lever 40 isslotted end of an adjustable link 23. The other end as at 42 to receive a block 43 which is pivoted to of the link 23 is pivoted to a lever which is actuthe end of the lever 23 shown in Figure 1.

ated by the distance type temperature responsive From the foregoing description it will be ap- 50 mechanism better shown in Figures 2 and 3. parent that the base plate 26, fixed shaft 27, Bour- Referring to these views, a supporting plate don tube 28, compensating spring 23 and operat- 25 is rigidly mounted on the rear wall of the ing lever 40, together with the capillary tube 32' casing 10. A base plate 26 is mounted on the and the sheath 33 constitute an. assembly unit supporting plate 25, and has rigidly secured which is supported by the supporting plate 25. 5s

In the manufacture of the thermometer, the end 34 of the sheath 33 is permanently secured in the clamp 35, and the base plate 26 is located on the plate 25 by means of the inner end of the shaft 2'7, which projects from the base plate 26 through an aperture 44 in the supporting plate 25.

Thus, to adjust the instrument for a zero reading, the base plate 26 may be angularly adjusted with respect to the supporting plate 25. This adjustment is permitted by the movement of the base plate 26 about the aperture 44, the base plate 26 being maintained in the adjusted position by means of clips 45 which extend over the outer edges thereof and are secured to the base plate 25 by screws 46.

It should be noted that the journal of thelever 40 on the shaft 27 is small, and results in a minimum amount of friction, there being no frictional contact of either the Bourdon spring 28 or the compensating spring 29 with the shaft 27. At the same time, this journal of the lever 40 insures a positive action thereof. In this manner both minimum friction and positive action of the temperature responsive mechanism are secured.

I claim:

1. In a distance type thermometer, a fixed shaft, a Bourdon tube and a compensating spring each spirally wound and concentric with said shaft, a post in which the outer end of said Bourdon tube is mounted, means connecting the inner end of said Bourdon tube to one end of said compensating spring, a lever journaled on said shaft and connected to the other end of said compensating spring, and means for securing said post in selected positions angularly adjusted about the axis of said shaft.

2. In a distance type thermometer, a base plate, a fixed shaft extending outwardly from said base plate, a Bourdon tube and a compensating spring spirally wound about said shaft and in spaced relation thereto, a lever journaled on said shaft and having an arm extending outwardly therefrom and secured to one end of said compensating spring, means connecting the other end of said compensating spring to one end of said Bourdon tube, and means for rigidly securing the other end of said Bourdon tube to said base plate.

3. In a distance type of thermometer, a base member, a fixed shaft projecting from said base member, a Bourdon tube and a compensating spring each spirally wound and concentric with said shaft and in spaced relation thereto, the

outer end of said Bourdon tube being secured to said base member, a connecting member secured to the inner end of said Bourdon tubeand extending outwardly therefrom and secured to the outer end of said compensating spring, and a lever journaled on said shaft and having a portion secured to the inner end of said compensating spring.

4. In a distance type thermometer, a base member, a fixed shaft projecting from said base member, a Bourdon tube and a compensating: spring each spirally wound and concentric with said shaft, the outer end of said Bourdon tube being secured to said base member, the outer end of said compensating spring being spaced a greater radial distance from said shaft than the inner end of said Bourdon tube, a connecting member having a portion secured to the inner end of said Bourdon spring and another portion secured to the outer end of said compensating spring, and a lever journaled on said shaft and having a portion secured to the inner end of said compensati s p i 5. In a distance type of thermometer, a base, a fixed shaft extending outward from said base, a Bourdon tube spirally wound about said shaft and in spaced relation thereto and having a fixed outer end secured to said base, and an inner free end adapted for rotary movement about said shaft, a compensating spring spirally wound about said shaft and in spaced relation thereto and having an outer end adapted for rotary movement about said shaft, an arm pivoted on said shaft and having a portion secured to the inner end'of said compensating spring, and means rotatable about said shaft but independent thereof and connecting the iner end of said Bourdon tube with the outer end of said compensating spring.

6. In a distance type thermometer, a support having an aperture, a base plate adjustably mounted on said support, a shaft carried by said base plate having one end projecting into said aperture, means carried by said support for maintaining said base plate in selected angularly adjusted positions about said aperture, 9. post on said plate, a Bourdon tube and a compensating spring spirally wound about said shaft, the outer end of said Bourdon tube being secured to said post, said compensating spring having an outer end connected to the inner end of said Bourdon tube, and a lever journaled on said shaft and having an end connected to the inner end of said compensating spring.

'7. In temperature responsive mechanism, a pivoted lever, a Bourdon tube and a compensating spring each spirally wound and concentric with the axis of said lever, the inner end of said Bourdon tube being nearer said axis than the outer end of said-compensating spring, means connecting said ends, and means connectingthe inner end of said compensating spring to said lever;

BEB'N'HARD: G, WARDENBURG. 

